Desiccation tolerance
The ability of organisms to survive near-complete loss of body water and resume normal metabolism upon rehydration.
Trehalose: A disaccharide sugar that replaces water around proteins and membranes, stabilizing them during drying. The classic protectant: it vitrifies the cell interior, preventing collapse as water leaves.
Resurrection plants: Angiosperms such as Craterostigma that dry to a brittle state and green again within days of watering. The rare flowering plants that tolerate desiccation as whole vegetative organisms.
Water-to-land transition: The evolutionary colonization of land by plants and animals, demanding defenses against drying. Desiccation tolerance is a prerequisite for surviving on land at all.
Seed bank: A facility storing dried orthodox seeds at low temperature for long-term conservation of crop and wild diversity. The applied form of seed desiccation tolerance, underpinning global crop conservation.
Rehydration damage: Membrane and DNA injury that occurs during rewetting, not drying, in sensitive organisms. The paradox that water itself harms cells returning to life is still being dissected.
Late embryogenesis abundant proteins: Intrinsically disordered proteins, first found in plant seeds, that coat membranes and proteins during drying. LEA proteins work alongside sugars to shield cell structures in the dry state.
Tardigrade: Microscopic eight-legged animals that enter a dry tun state and survive years without water. The most famous desiccation-tolerant animal, dried in a curled tun and revived on contact with water.
Embryophyta: Land plants as a group, all of which protect their embryos and most of which retain some seed or spore tolerance. Ancestral vegetative tolerance was largely lost and kept only in spores and seeds.
Anhydrobiotic engineering: Attempts to make sensitive cells and drugs dry-stable by introducing sugars and LEA-like protectants. The direct engineering project built on desiccation-tolerance mechanisms.
Intrinsically disordered proteins: Proteins lacking a fixed three-dimensional structure that function in protection and signaling. Many protective proteins only fold or act in the dry state; how they work is unsettled.